XC6221
Series
■OPERATIONAL
EXPLANATION (Continued)
<Current Limiter, Short-Circuit Protection>
The XC6221 series’ fold-back circuit operates as an output current limiter and a short protection circuit for the output pin.
When the load current reaches the current limit level, the fixed current limiter circuit operates and output voltage drops.
When the output pin is short-circuited to the V
SS
pin, the current falls and reaches about 30mA.
<CE Pin>
The XC6221 internal circuitry can be shutdown via the CE pin signal. In shutdown mode, output at the V
OUT
pin will be
pulled down to the V
SS
level via R1 & R2. However, with the XC6221B/D series, the C
L
auto-discharge resistor is
connected in parallel to R1 and R2 while the power supply is applied to the V
IN
pin. Therefore, time until the V
OUT
pin
reaches the V
SS
level is shorter. For the XC6221A/B, the output voltage becomes unstable, when the CE pin is left
open. For the XC6221C/D, the output voltage becomes V
SS
level because the CE pin is short-circuited to V
SS
via an
internal pull-down resistor. However, the CE input current will be increased via a pull-down resistor when the IC
operates. If this IC is used with the correct output voltage for the CE pin, the logic is fixed and the IC will operate
normally. However, the supply current may increase as a result of shoot-through current in the IC's internal circuitry
when a medium voltage is input.
■NOTES
ON USE
1
.
Please use this IC within the stated absolute maximum ratings. The IC is liable to malfunction should the ratings be
exceeded.
2. Where wiring impedance is high, operations may become unstable due to noise and/or phase lag depending on output
current. Please wire the input capacitor (C
IN
) and the output capacitor (C
L
) as close to the IC as possible.
9/23
TOREX [ TOREX SEMICONDUCTOR ]
